I've had that problem, and am off and on still fighting it.
It definitely sounds like acid reflux. Question is what is causing it. Reflux can be caused by a kazillion things—like to name just a few ulcer, sleep apnea, sleep position, hernia, thyroid issue, stress, chiropractic issues, gallstones, hormone imbalance, allergies or sensitivities, an imbalance in digestive enzymes, and so on and so on. Complicating it even more, any of those causes could be caused by something else (like thyroid issues may be caused by being deficient in iodine). It's a vicious circle!
Definitely, as suggested by others here, watch your water intake.
Also cut out soda pop, caffeine (coffee and tea), chocolate, and tomatoes—they're acid causing. Try to make note of any foods or drinks or even medicines or supplements that may make things worse (like dairy, or other potential allergies or sensitivities like gluten, eggs, etc.). Yes, maybe you didn't used to be allergic or sensitive to some of these foods, but they can develop over time.
Try sleeping with your head elevated (might try raising the head of your bed on blocks a few inches).
How has your sleep been? There IS a connection between apnea and reflux—with apnea, when you stop breathing and suddenly start again, it causes a vacuum sucking effect in the throat pulling stomach acid up into the throat (and in some extreme cases further up into the tubes to the ears!); making it another vicious cycle, the reflux then damages the nerves in the throat, causing it to close up, and introduces another breath ceasation which will then spur more reflux, etc.
Definitely over all, focus on overall nutrition and detoxing the body. Good nutrition and a "clean" detoxed body may clear up whatever of the kazillion causes of the reflux may be.
In my case, I'm pretty sure my reflux throat issues are allergy or sensitivity caused, and do affect my sleep. I just haven't been able to pinpoint the culprit. It gets better for me if I take antihistamine. But I do think the allergy will go away after I finally get purged of all the bad stuff that I'm trying to kill off or kick out with iodine, Essiac, colloidal silver, oil pulling, and dry brushing. I have noticed since this started up for me that it's worst May-August, which makes me think mine is allergy caused, despite allergy doctors saying I'm not allergic to anything (conflicting reports there, as testing I had 16 years ago said I DO have allergies, and testing I had a year ago said I don't). All these therapies have reduced my problem and I think will eventually cure the "allergies". However, for now I just have to persevere and also avoid the foods that make the reflux even worse like my mother-in-law's spaghetti (yeah, I know some of you are going to joke about that, but her spaghetti DOES taste good, and I do like her a lot—she's a gem).